During the current year we shall continue to develop and evaluate videodensitometry sampling circuits which allow us to simultaneously sample from multiple locations over the lung. As our prior work has demonstrated, we must do a careful analysis of a major portion of the visualized lung fields and relate both ventilation and perfusion information to detect pulmonary abnormalities. Substantial developmental delays in hardware production have precluded patient analysis during the prior year and for that reason patient data sampling will be instituted in the coming months as our sampling equipment finishes development and is ready for field trial. BIBLIOGRAPHIC REFERENCES: Silverman, N.R., Higgins, C.B., Rosen, L.: Myocardial contractility analysis using videodensitometry. In Videodensitometry (ed. M. Marchal). American College of Radiology 1977, in press. Silverman, N.R.: Whole Body CT Scanners - Science, Not Science Fiction. San Diego Physician 63:22, Jan 1977.